Nitrite as a Physiological Source of Nitric Oxide and a Signalling Molecule in the Regulation of the Cardiovascular System in Both Mammalian and Non-Mammalian Vertebrates

摘要

The circulating anion nitrite (NO2n-n) has long been considered an inert oxidative metabolite of nitric oxide (NO). nOver the last decade several studies have identified inorganic nitrite as a key player in many biological processes because nit acts both as a principal storage source of NO and as a signalling molecule distinct from its link with NO. This new field nof research involves the exploration of the molecular, biochemical, and physiological activities of nitrite under a variety of nphysiological and pathophysiological states. As a signalling molecule, nitrite is involved in various biological responses, nincluding hypoxic vasodilation, inhibition of mitochondrial respiration, cytoprotection following ischemia/reperfusion and nregulation of protein and gene expression. As a stored form of NO, since the cardiovascular system is under an important nNO-mediated autocrine-paracrine control, intensive investigations involve nitrite effects on vessel and heart regulation. nRecently, some authors have reported that nitrite, through both direct and indirect pathways, plays a fundamental role in nvascular homeostasis and cardiac function not only in mammals but also in non-mammalian species (fish, amphibians). nThis review highlights some patents and the importance of the signalling properties of nitrite anion in a comparative nvertebrate context for providing significant insights on “ancestral” functions of the nitrite-NO system, which may nfacilitate its potential use as a therapeutic agent of cardiovascular disease